The objective of this proposal is to support the participation of young investigators at the XV Testis Workshop on Spermatogenesis: Regulatory Aspects. The XV Testis Workshop, which is sponsored by Serono Symposia, USA, is scheduled for April 7-10, 1999 Louisville, Kentucky. Young investigators are defined as those within 5 years of receipt of their PhD. Funding is requested to provide 15 awards of $1,000 each to cover travel and living expenses during the Conference. Serono Symposia, USA will waive the registration fee for the awards. Applicants will required to submit an Abstract of their presentation at poster session and these will be judged and the awards made by the Chair of the Testis Workshop and his Scientific Advisory Committee. Conceptual advances in the biological sciences are marked by the application of the new techniques and experimental strategies. Nowhere has this generic principle been more apparent than in the study of testicular cells as judged by the evolution of themes presented at the Testis Workshop over the past 25 years. Keeping to this tradition, the 1999 Testis Workshop is structured to offer fresh insights and approaches for understanding spermatogenesis from sex determination to fertilization and will include a session on genetic defects and remedies. It is the hope of the Chair that the investigators participating in the meeting will be stimulated intellectually and encouraged to pursue cutting edge research in an area that is exceedingly important to reproductive health